A Prototype of Compact Digital Holographic Microscope with Mach-Zehnder Configuration

Digital holographic microscope (DHM) is a non-destructive imaging device to obtain three-dimensional (3D) images of microscopic objects. In this research, we design and implement a prototype of compact digital holographic microscope system to obtain 3D images of multiple objects placed horizontally. The features include the use of Mach-Zehnder interferometer with vertical beam propagation, the addition of four mirror mounts and three micro shafts to provide accurate beam adjustment, a modified electronic circuit as intensity regulator to control laser intensity, and the inclusion of Canon EOS 1000D as the image detector that allows wider intensity adjustment by means of the ISO setting and shutter speed. We check the system performance using two types of test objects, namely, multiple sugar grains and USAF 1951 resolution target. Experimental results show that the prototype can reconstruct 3D images of multiple objects and USAF 1951 line patterns up to 5.66 lines/mm.